Best available cop



BEST AVAILABLE COP".

Nov. 11, 1924.

L. D. KELLOGG v TELEPHONE SYSTEM Filed Jan. 4,

572/527702". gag/. f1 YZ/U BEST AVAILABLE COF"l Nov. 11, 1924.

L. D. KELLOGG TELEPHONE SYSTEM I5 sheets-sheet 2 Filed Jan. `4, 1919 jim/5277021' f5/"0 Effe/ZZ:

BEST AVAILABLE COP.

Nav. 11, 1924.v l 1,515,345

L.. D. KELLOGG TELEPHONE SYSTEM Filed Jan. 4. A1919 5 Sheets-Sheet 3 vezzn' BEST AVAlLABLE COPX Nov. 11,-4 1924- A L. D. KELLOGG TELEPHONE SYSTEM hummm RUN 5 Sheets-Sheet 4 #www rw kw Filed Jan. 4, 1919 BEST AVAILABLE cof.

Nov. 11, 1924 L. D. KELLOGG TELEPHONE SYSTEM Filed Jan. 4, 1919 5 Sheets-Sheet 5 Vin/527 725 LEPUyZ/ WNLMDQNWN Patented Nov. 11, 1924.

UNITED STATES BEST AvAaAeLE cop..

PATNYT OFFICE.

LEROY D. KELLOGG, OLEACIEIIICAGQl ILLINOIS,

AND SUPPLY COMPANY, OF

App'ncatien mea January 4, 1919'.- 'serial No. 269,578.

contacts divided into groups', Aand cd-o'perat-I ing movable .contact "makers adaptefdito receivea primary. adjustment to" select agroup of contacts and/thereafter; a secondary 'ad'- justment to select a.v in the' elected U'roup. My invention has to do more 'pari Y, icularly with.' the mechanical construction of the Aabove-ni'enti'oned"type fof' switches', and' with" the circuit, arr:ingeriientsI adapted for use with'the switches. f Prior to my invention systems f the socalled two-wire type,l which 'the-"switches are controlled over th'.`.two sides of a: circuit in; "Series, have been" provided`. lvvith "slowactingrelays or speci Illy'fpostructed and adi usted' 'relays to 'ecrire 'the necessary -ci'r cuitichanges'in systeinsofthsl.characterf It is an object of iiyi'livetion toproduoe a'system of the so-ealld' two-'wiretypen which all of thel switchrelays'arel-ofthe ordinary type and are-,not slow'acting or specially constructed and adjustedv to secure the "necessary circuit' changes, to operate switches of thel tWo-'dimension'type over the two sides of a circuit in series.

'A further vobject of my invention is the production of a' switch structure lwhich is provided 'with an operating magnet that moves the carriage ofthe switch in one direction for both the groupA selecting operation and for the contact'selecting operation in the elected group.

It is a further object ofmy invention to so arrange the switch structure that the one motor magnet not only advances the switch carriage, but also returns the same to normal position.

Further objects of my invention reside in the meansprovided to advance andV return the switch, the novel manner in which the switch operates to select an elected vgroup of contacts, and the unique method in which the dilerent circuit changes are brought about. i

A further object of my invention is' to produce an improved switch structure and co-operating circuit which embody desirable features and advantages all in a simple, eicient and economical manner, which is most'eicient and economical in its opera- AssIeNolav To KELLoGG sWIioIIBoAnD CHICAGO, ILLINOIS, A CORPORATION or ILLINOIS.

tion, and which has its parts so constructed andv combined as to make them readily accessible for repair and adjustmer'xt.A :Other features of my invention' will be more particularly pointed lout-in 'the fol# lowing specification and in" the appended clai'nsnf For a more complete understanding of my invention, reference'may be hadv tothe accompanying 'drawings in` which like reference 'charactersl denote like parts inf the dif'- erent views,'and inwhich'zl- 'I Fig." 1"is a front elevation ofthe switch structure off my invention f Fig, 2 is a plan view'of; Figi 1 Figi?) fis 'a bottom view 'of Figi 1;'

`Fig. 5-,is a side `el'evation'oi a modiied form'of'dijiving mechanism for'the switch as-illustratedv-in-Figs. 1 to 4;' f *''Figil'isfa'plan view ot-Fig.V 5': "fFig "7'isa: side elevationo'f a. circuit changing' switchwhich operates in connection with the driving mechanism 'ot' Fig. (i:

'Fig 8 is 'a planview 'of Fig?? Fig. '9 is a side elevation-of' a connector switch structure," f

Fig. 10 diagrammatically shows a' group selecting switch, and Fig.`11, which comprises parts 1. 2 und 3, is a diagrammatic illustration' of the circuit adapted to be 'used in connection with the switch structures of my invention'.

The apparatus illustrated in Figs. 'l to 10, inclusive,'is themechanical switch 'apparatus and its associated mechanism for use in connection with the circuits shown in Fig. 11, parts l, and 3. Reterring'rst to the switch structure illustrated in Figs; 1 to 4, inclusive, in which the preferred form of the selector switch is shown. it comprises in eneral a suitably supported carriage C slidably mounted and which is adapted to he moved ina horizontal direction hv means oi a motor magnet MM. A secondary carriage BEST AVAILABLE con.

SC is suitably supportedby a frame which is in turn supported by the main carriage C. The secondary carriage SC carries a relay TVVR which is supplied With'a 'Wiper carrying arm WA which arm supports the wipers W and the group wiper GW. A bank of contacts B suitably supported is operatively associated with the Wipers WV and a set of group contactsuGC., is operatively associated with the group WiperGVV.

Referring now more in detail tothe switch structure as illustrated, it comprises a carriage C slidably supported upon rods 2 and 3, which rods pass throughsuitable openings in the carriage C. The rods 2jand'3 are supported by end plates 4 andv 5, the said end plates 4 and 5 beingprovided with suitable angular portions 4 and by which the end plates 4 and 5 are secured to a basev 6., A motor magnet MM is provided lfor moving the carriagelCand comprises a heeliron 7, armature 8, 'anda'n electromagnetQ, thevsaid motor magnetMM as a unit being suitably secured to a bracket which bracket k10 is in turn secured to the base 6. A set of'interrupter springs' 3 and74 `are operatively asso ciated with the. armature 8 andare mounted upon the heel iron 7 but insulated therefrom. Racksll and 12.are supported on the carriage C by means ofyoke pieces 13 and 14, which yokes aresecureduto the carriage C by means of screws 15.v The racks 11 and 12 are slidably supportedin the yokes13 and 14 and they are provided with a plurality of teeth which are for (5o-operation4 with' the pawls 16 and 17, respectively, to'rnove the carriage C in two directions. Thesaid pjawls 16 and 17 are pivotally supported by the armature 8 of the motor magnet The suc vessive energizations of the motor; magnet MM, as will be more fully hereinafter described, cause the paWl 16 to engage sucwessive teeth of the rack 11, thereby moving the carriage C in a horizontal direction. The selector switch of my invention is adapted to take twenty-two steps and upon the twenty-second step, the carriage C lis in its foremost position. Vhen the magnet MM causes the carriage to take itstWenty-second step, the plate 18 secured' to the rack 12, which is provided with a cam edge 19 engages a rod 20, Whichrod 2O is suitably secured to the base 6, and as the racks 11fand 12 are slidably supported by means of the 'Jokes 13 and 14, the rack 11 is moved until the teeth of the same are out of engagement with the pawl 16 and the rack 12 is moved in the position occupied bythe rack 11, so that the teeth of the rack 12 are operatively associated With the paWl 17. so that the carriage may be stepped back to normal by the motor magnet MM, as will be more fully hereinafter described. When the carriage C is being restored and upon the twenty-second return step a plate 21, similar to that of 18 and lsuitably securedk to the rack 11 and also provided with a cam edge 22, engages a rod 23 which causes the racks 11 and 12 to be moved in the direction opposite to that upon the forward motion of the carriage C until the paivl 17 is free of the teeth of therack 12 and the teeth of the rack 11 are again in operative relation with the paw] 16, so thatthe carriage may again be stepped in a forward direction. To keep the racks 11 and 12 in their different positions, I provide a spring 24 suitably secured to the carriage C, as clearly illustrated* in Fig. 4. Notches 25 are provided in the racks 11"and 12 which arev engaged by the sprin'g24de- .Y

pendingfupon the positions of the racks 11 and 12. The spring 24 and'notehes 25fareso arranged that when theracks 11 and 12 start to move from one position to the otherg'th said spring and notches'cofoperate"tofsnap or assist the racks :into ,positionly A rack26 issuitably secured totheside ofthe carriage C by means of scre\vs"27,'and is` provid'edwith a plurality of notches Whichfare'succ'essively engaged by a spring 28 to hold the saidcaif riage C in its different positions Awhen:bfe'i'n'g advanced'step by stepy by the energi'zations of the motor magnet MM. The spriiigx28 is secured to a suitable bracketl`j29, fwhieh bracket 29 isin turn securedto the'base-G. The spring 28 co-operateswith.;the.not'ch`es in the rack 26 in such a manner that the spring 28 assists or snaps the carriage C from one position to the other when 4the magnet MM isbeing operated. The secondary carriage SC, as before mentioned, is slidably supported by the carriage support 30, in the following manner;V 'The side plates 31 and 32 are pivot'ally secured to a block 33 by means of pivot screws 34, the said `block 33v being securely fastened to the carriage C in any desirable manner. V vThe forward end of the carriage supportrests upon a block 35, which block is secured to the carriage C. The carriage SC comprises a block 36 slidably supported by means ofa square rod 37, which rod 371 is secured at its ends to the cross pieces 38, which cross pieces are in turn secured to the side plates 31 and 32. The secondary` carriage SC supports a combined test and Wiper control relay TYVRY. the said relay comprising a heel iron 39,. electromagnet 40, pole piece 41, armatures 42 and 43. and a set ofcontact springs 68, 69, and 71 mounted on the bracket 72 and insulated therefrom, the said springs. being operatively associated with the armature 43. The armature 42 is pivotally supportedby the heel iron 39 at 44 and is provided with an extension 42', which extension 427 forms a support for the Wiper carrying AarIItlDX which is in the form of a rod' 4,5pivotall'y supported-by the extension; 42'..I The arm 45 is provided with a sto-p.l 465which, engages a stop 47 in the extension 42 and is held in icio BEST AVALABLE CCPL I described;-` The Wiper carrying arm WA supportsjagroup 'wiper'l andthe line'wipers 52 and 53, privatewviper'54 1and auxiliary Wiper 55,'the said Wipers 51, 52, 53, 54 and are secured to the arm 45 and properly7 insulated vfrom the arm 45 andifrom each other.

"'I'provideasetof group contacts GCcomprisling-ten' contacts 56 supported upon the plate f 57 and 'insulated therefromV and from each` other, for co-operation Withjthel Wiper GW., `The, contact bank comprises ten groups of contacts, each' i group of contacts comprising ten sets'of four contacts, each; each setfincludmg vline contacts 58 and59, a

x privatefcontactrGt) and .an auxiliary contact f 61, the said'contacts being operatively associatedvvith'the wipers52, 53, 54 and 5.5. The sets ofcontacts'58, 59, 60 and 61 are supported by` plates62 which plates 62 are. angularlydisposed yin relation With the group contacts 5.6.. ,'Ilerminal's 63 are provided .for thecontacts "58, 59, 60 and'61,ftli'e said terminals 63 being also secured to the plates 62. The terminalsf63, are connected to the bank contacts 58,759, 60 and '61 by means of fine conductors not shown. The bank Wires (not shown) areconnected tothe bank terminals 63. Thefplate's 62'are provided with angular Vportions 64 inthe form of a rail, the said rails 64 being provided with a plurality of notches 65 `Which are successively engaged by the arm when the'ivipers 52, 53, 54 and move over the successive sets of contacts 58, 59, and 61 in search of an idle set of contacts. he group Wiper 51 is pro- 7- vided With an angular portion 51 which is adapted to engage the angular extension 56V of the group contacts 56. A U-shaped niember 66 secured to the extension 42 in a suitable manner has its depending arms 66 resting in the notch 67, whereby when the side pieces 31 and 32 are moved, t-he magnet 'F1-VR and its associated mechanism will also be moved. A set of normally closed contacts is insulatingly secured to the end plattl 4 and when the` carriage C is in normal position, 'an insulation button 76 carried upon an angular bracket 77 holds the contacts 75 in their normal position, but upon the first step of the carriage C oit' normal, the contacts 75 assume their alternate position. Three sets of contacts 78, 79 and 80 are insulat-ingly mounted upon the end plate 5 and upon the last step of the carriage C, insulation buttons 81 secured to the bracket 82 engage the spring sets 78, 79 and 80 and move them to their alternate positions. A plate 83 suitably secured to the base 6 serves asa mounting means for the conducting strips 84, 85, 86, 87, 88 and 89, the said strip 84 being engaged by the AWiper 90, strips 85,' 86 and 87 by the Wiper 91 and the strips 88 and 89 b v the Wipers 92 and 93 for controlling circuits, to be'hereinafter described.- -While 1 have shown a certain combination of contact strips and Wipers, I do not wish tobe limited to the same asany number ot'- contact Wipers and strips may be providedas found necessary to control any specific circuit arrangement. I

Referring' now to the structure as illus'- trated in Figs. 5 and 6, I show a modified form of driving mechanism tor the selector described and illustrated in Figs. 1 to 4,-in'' elusive. Then using the driving mechanism as illustrated in Figs. 5 and 6, the motor magnet MM, racks 11 and 12 and-the shifting mechanism for the racks 11 and 12 are dispensed With and the rectangular 'shaped frame is substituted and isvsecuredto the bottom of the carriage C. The mea-ns for driving the carriage C in a-horizontal direction will nov.7 be described. A common driving shaft 101 is provided and supplied With a plurality of driving Wheels l102 such a Wheel as 102 being vassociated with-each switch of a group." 'I`heshat`t '101*iscentrally located in relation tothe frame 100 andfthe drive Wheel 102 is in frictional engagement with a wheel 103 loosely journaled'on a shaft 104. Plates 105 and 106 are provided each being provided with an arcuate Vslot 107 in which the shaft 104 rests. The wheel 103 and the shatt 104 upon which the Wheel 103 is mounted as a Whole is centrallylocated 'in relation to the trame 100 and is held in 'its intermediate position in the arcuate slot 107 by means ot' the springs 108 and 109, the said springs being suitably mounted upon a bracket 110 by-means ot' rivets-111.l The free ends ot' the springs 108 and 109 engage collars suitably secured to the shaft 104. To move the wheel 103 into engagement with either the faces 112 and 113 of the frame 100 to drive the carriage C forward or back- Ward, I provide-a pair of operating magnets 114 and 115 supported by the heel iron 116, which heel iron 116 is in turn secured to a base 117. An armature 118 is pivotally supported by the heel iron 116 and rests between the magnets 114 and 115. The. armature. 118 is provided with a lutin-cated end 119. and a collar 120 isplaced on the shaft 104 and rests inthe bifurcated end 119'ot-armature 118.

Having described the apparatus. I lwill now describe its operation, assuming first. that the carriage C is to be moved forward, the magnet 114 is energized attracting the armature 118. The biturcated end 119 engaging the collar 120,- moves the Wheel 103 BEST AVAILABLE CCPl and shatulO. as a whole, in the arcuate slot 1 07, against the tension ot' the springs 108. The wheel 103 now engages the face 112 of the frame 100, and as the wheel 103 is in frictional engagement with the driving wheel 102, transmits motion to the `frame 100 to move the same. Since the frame 100 is secured; to the carriage C, the said carriage C is moved in a forward horizontal direction until the limit of its forward motion is reached when thel circuit of the magnet 114 is opened and the spring 108 now. moves the wheel 103 to its intermediate position. To restore the carriage to normal, the magnet 115 is actuated to attract the armature 118 and the bifurcated end 11i) engaging the collar 120 on the shaft 10-1, moves the wheel 103 into engagement with the face 113 of the frame 100 against the tension of the spring 109, and a rearward horizontal motion of the frame carries the carriage C to normal, and when the carriage C returns to normal, the magnet 115 restores. Due to the action of spring 109, the Wheel is restored to its intermediateI position out ot' engagement with ,the face 113 of frame 100 when the frame has again reached normal.'

To accomplish the energization of the magnets 114 and 115, respectively, to transmitmotion to the. carri; 9e C in either direction, Iprovide a circuit changing mechanism clearly illustrated in Figs. and 8. The circuit changing mechanism comprises an interrupter disk 121, star wheel 122 and a ratchet 123, all of which are supported upon the shaft 124, which sha-ft 124: is suitably supported at its opposite: ends in the plates 125 and126, which plates 125 and 126 are seciued toa base 126. The interrupter disk 121 is provided with a plurality .of notches 127 and lugs 128 upon the peripheral ring 129 whichl is of suit-able insulation material, the said notches 127 and lugs 128 are operatively associated with the spring 131 of the spring set which comprises the springs 130, 131 and 132. The springs 130, 131 and 13 2 are insulatingly mounted upon a suitable bracket 133 which bracketl 133 is in turn secured to the base 127. stepping magnet 134 is provided and' comprises an electromagnet 135, a heel iron 136, an arma.- ture 137 and a paw] 138 pivotally supported upon the forward end of the armature 13T, the said pawl 138 being spring pressed into engagement with a tooth of the ratchet 123, The stepping magnet 134 as a whole is secured to the base 126 by means of screws not shown. A roller 139, spring pressed into engagement with the star Wheel 122, is pivotally carried by the support 140.

Non", upon the energization of the stepping magnet 134, its armature 137 is attracted, causing the pa-wl 138 which engages a tooth ot the. ratchet 123 to rotate the interrupter disk 121, star wheel 122, ratchet 'an @Hrslzmggclrcmt fer. the megas 123 and shaft 1241.l one ste Irrojyjeinenltl of the interrupter disk ca-uses the, 131 which normally restsupon the 'periphery 14:1 to disengage ythe -same and tlropfii'i ofa notch 127 inthe interrupter This'. movement of spring 131.causit-tg engage its associated contact132 'to close a, for, say the magnet 114 the driving mechanism just described; magnetll: upon actuation attrm'its'l its armature" I1,18 causing ,the wheel 103, to be moyedfin't'oeligagement with the sui-face 1120i the 100. This causes aA forward moveinfen t.l 0j the carriage C and wvllenfthe said' carriage C 1-eaclies-thelimit of., trz'ivel,- meansl are actuated Ato open the circuit. o f the magnet 131. "When the star 'vheel1221's rotated one step as just' thtf-Illt-r 139 and its supporting arm 142 areffoiced, out against their no 1jrr1a, l 'tension4 and lt e roller engages a tootlr'of thestar gheel'l, Now, upon thev retraction; ifjtli'e 'a1ji i iat uie 137 of magnet 134, theroller', 'due'tjo". spring pressed action, rotates', the; interrupts da` 1.2.1, rachet. 12a-'antler wheel 122 the distancegomone'step, @this movement o the inteivrupter d isl:A 121,. euses the spring 131 ro navette stigma? aaa, 'ai again engage the rerrheimlftl-qhe iel his allows the 4.s pring 131.16, disengage spring i132 to open the @mimi-a' 114, allowing the carriagetO llanni s advanced position. having been 1nyd,lt1i"nwl!38 new. 1.1- gages the next th oftheratchet To return the carriage C .to iiforrijalpmeansai actuated to operate the steppi'pgriviiet again, and the armature 1,31 alractibii causes the'paivl'138ftofstgpi'ltlieiit" 'i i Sk 12.13' Stai?. \hee1,1 `22,j 'ratletlw'a Shaft 124 01.1.6. aber. The. t' eifrig of, interruptr disk 121 eusstlifrerphel' 1411 to disengage: the ,springn'l'antl .causes the lug 128 to -,engage thefspriiigi llfinovinf it into engagement wh." thebpfagl The closure' oi ,contactslQ ClSS naaf the driving mechanism and its' '118 is attracted', causing the ivh'ell103-tojeiigage the surface 113 of the'frame 1[0Q,'c:i.us}n`ig the carriage C to be movedito normal position, vand when this position is ijeich' i means areactuated, toiopenptlie eiie'rgi ng circuit of the stepping magnet liunjl'iicli magnet retracts itsarmaturedff allowing the spring pressed roller 13' ),`t o n1fove."tlie star wheel 122 another ste as 'abgvef scribed, and this step 'whim 1s 'also 'taken by the interrupter' diskA 121, causes tlreflug 128 to disengage the sprintf 1 31Janda' allow the spring 131 to enga-ge'tlieperipwery 111 ofthe disl 121 ,`placingftlie in an intermediate 'position betiveenl" tlre sp1-ings 130 and 132. 'I he opening ofE c o'rif it-ts 130 und 131, opens the eiiegrgiailnghcirj los BEST AVAILABLE COF,

cuit of the magnet 115 allowing it to retract its armature 118, disconnecting the wheel 103 from the face 113. The ratchet 123 having been moved also, allows the pawl 13S to engage the next tooth of the ratchet 123. This sequence of operation of the mechanism is continued for the advancement and restoration of the carriage C.

Referring non' to the connector mechanism as illustrated in Fig. 9, it comprises mechanism similar in construction to that described in connection with the selector illustrated in Figs. 1 to 4, inclusive. lt comprises in general a carriage C and a secondary carriage SC', a stepping magnet MM2 and rack shitting mechanism. The test relay vll-R2 associated with the secondary carriage SC is somewhat different in construction as is also the secondary cal'- riage support, as will now be described7 The relay Tl'lR2 is provided with a pair ot' armatures 42 and 432 pivotally supported by the heel iron 30', and a pair of pole pieces 41 and 412 are provided for the armatures 42 and 432. The side supports 31 and 32 are provided with a plurality of notches 50 with which armature 432 i's operatively associated. Now, when the switch is in its normal position, the arm 66 of the member 663 rests in the notch 67. When the motor magnet MM2 is energized and cle-energized, as described in connection with Figs. 1 to 4, inclusive, the carriages C and SG are stepped in a horizontal direction by the magnet MM2 until 'the group wiper engages a group contact which is grounded, due to the said contact being preselected by the tens group selecting switch. Then this grounded contact its engaged by the group wiper, the relay TlR2 is energized, attracting its armatures 42 and 432 and the attraction of armature 42 withdraws arm 662 from the notch GT and places wiper arm 45 in engagement with the inclined rail 64 of the selected group and the attraction ot armature 432 withdraws the nose of the said armature from the engaged notch tinues to step the carriage C 'orwardafter the group contact has been selected, but the secondary carriage SC as this movement ot' carriage C continues, remains in itsl adjusted position, due to the nose of armature 432 having disengaged notch 50 and the `wiper arm 45 engaging the rail 64. Upon the eleventh step of the carriage C and carriage support t'or carriage SC', the relay T`WR2 Cle-energizes, allowing the nose of armature 432 to engage a notch 50. The

continued energization and de-energization oi magnet MM2 continues to step lcarriage C in a horizontal direction and as armature 432 again engages a notch 50', the secondary carriage is again moved but. in an'angular direction, due to the arm 45 engaging the The motor magnet MM2 con--v inclined rail 64, the Wipers engaging successive sets of contacts and when the wipers engage the contacts of the wanted line, the private contact is grounded, due to its ha ving been so conditioned by the units preselector, and this grounded contact again closes an energizing circuit for relay TWR2 which again attracts its armature 432 again disengaging itsnose from a notch 50. The movement ot' carriage SC is thus arrested and the wipers remain in engagement with the selected set of contacts due to the arm 45 engaging a notch 65 in the inclined rail 64. The magnet MM2 continues to step the carriafre C and carriagesupport for carriage SC until carriage C reaches its foremost position at which time the shifting mechanism shifts the racks, as already described in connection with Figs. l to 4, inclusive.

'In Fig. 10, I show a group selectingl switch, one of these switches being provided for each selector switch. This switch is also used as' artens and units'pre-seleetor for' the connector switch, that is, two switches 'of this character are pro'vided for each connector. The switch as shown comprises a" drivingmagnet 219, an armature 401 provided with a driving pawl 402 ada ted to rotate fthe ratchet 403* for each d energization of the f magnet `219.` f A wiper 222 is carried4 by the-ratchet 403 and 'is adapted to engage the 'lbankf contacts 223. 'Afset of oft-normall contacts 224 is also provided as well as a retaining pawl407. Thel retaining pawl 407 is adapted to be tripped by the switch carriage@ or C of the selector or connector switchfdepending upon-:which of these switches this apparatus is associated with; Said retaining pawl is normallyiheld out of engagement 'with-ratchet 1403. A complete" description ofthe operation of this apparatus will be'hereinafter given. 'Referring nowto' Figure'1'1,"which comprises Sheets 1, 2-and 3,11 here' show the necessary apparatus for ,establishing a connectio'n'between a' callin -subscriber A and aiall'ed subscriber'H; nSheetfli, I show a calling substation 2A, together with its line circuit'equipment L, located at the central voiice, an operators cordT circuitD,'together with an operatorstelephone-set O'gfand ay set of multilple jacks.; -TJ connected to a trunk circuit` leading"l to a first selector switch E, Ashowncn Sheet 2. The selector switch E shown Aon Sheet 2 is adapted to extend connection t'o a second selector switch E shown on this sheet'. The second selector switch F isadapted to extend aconnection to the connector switch Gr shownpo'n Sheet 3, which connector switch is adapted to extend a connection to the called substation H shown at the right of Sheet 3, together with its line circuit equipment L.

The substation A, shown on Sheet 1, and

show-n iniJiUsl. tolO, inclusive.

BESTA the substation-H,lshoYn onSlieet 3,.are of l he ordinary` Kellogg; connnon I battery type,

While. the line circuit equipment Ldand L contailrthe usual line relays andgcut-.oliVl relays? together wit-h n'iultiple jacks .l vand J. respectively. The cord circuit D is provided with the necessary supervisoryv apparatus,1 -togetherA with anaoperators lcalling deviceID, which is diagranunatically lllUS" otthis apparatus )till behelrfinateiggiyen vwhen 4the manner in `which a; fz-fortiplete'1V con nection is .established bet/.Ween the/ V calling subst-ation 'A andthe called substationi lH- is given. l'

EheV connector switch G is) prov ided; with the, necessary fr elaysl contacts, Wipers,1fing ingy generator, intem'upters,- izetc., Aas to -permit` it-tof operate with v the switch structure Likewise. a complete escriptionbfthe operationot' Athe I connector. lsWitch Will hereinafter given. w Thesystenl 1s-shown, isofthe 4Wiellw `lgnown Lundquisttrunking s y-'ste'in type, and is of 10,000fline capacityybeing -provided with first selector, second selector' and connectors. L If itis desired to i11Grease-,;thej capac-ity ofthefsy'steni, althird selecto-r ,may be added, While` ifit is-.desired toidecrease the capacity.;oiethesystenu Lthe, secondi selector and eventtheA lirst selector '1n'ay` be dispensed with andgijche trunkjacks con-.

n ectedg'Y directly f through to the conneeto r switch G.' f A- .l 'Y Referring now more in.. l etail to niy invention as .illust-rated and assrmiing `that the subscriber atithecalling substation A initiates afalh'ithe removal of the re cei ver at the'calhngsubstationA establishes an energizing circuit ortheline relay LR- of the linecircuit. L, traced fro1n,batt ery through, the winding fof line ;1'ela'yLR.y normal contact 200 ofthe 'cut-ofi' relayCO, throughthe, substation. A to ground at normal contact- 201'ofthe cut-off. relay-@0. The linerelay LR upon.energizationcloses its alternate Contact to establisha circuitfor theline signal S traced from battery through the lamp S4 to' ,ground al1/,theA alternate Contact offlinerelayzLR,gwliichcauses the said signal Sjto gloW. he. operator noting-the .lighted signal;- S, .insertsfthe answeringgplug `A'P otth'e cord circuit-D into the answering 'jack I otrthecallingline1 establishing an energizingci1'cuit;l for the cut-oil' relay lCO traced. troni-ground through the' Winding of the1 said relay 1GO', sleeve contactsofv the connected plugAP and-jack J, normal cOntaCt- QOZQ supervisory relay Y, SR, through the 1;si'ipeIIViSQ'ry.v lampaAL t0 VAILABLE COF,

. lblatteiyz and-ground. i fThe l relay CQ upon lenergization j opens its norriial contacts 200 ancl20l interrupting the, circuit of line `relay LR, which relay LR restores and elta-ces y the line signal S. The inserti on ofthe answering plug AP into the jack .T ofthe calling line also establishes an energizing circ-uit for the supervisory relay-"fkSR, ltraced from battery through theupper Winding of the relay SR, the tip contacts ofthe con-.

nected plugAP and jack J, throughl ,the substation- A .t-hrough ring contacts o.f .t`he connected jack Jgandplug APitohground through the llower winding ot' ,the-v super- `gizingl closes its valterna-te'contactgQlli closing Ya substitute circuit forthe cut-'off relay traCBCl from battery through alternatecoir tact; 203, fsleeve contacts of -theco-nriected plugQAl) and jack I to groundthrouglrthem35 A. privatefcontacts' i204l of the connectors associated with' the calling lineare niadebusy. due to therbatterypotential placed upon1the sleeve of. the jackl when the plug is insertedm"0 into the jacl: J ol' the calling line. .TfIhis battery potential extends over conductor 205 to the privatecontacts 9.04,` thus n 'iaking them lousyt against Vall incoming calls which may Y be extended to the .calling subscribe 1:-, 93

now iijiquiresthewants' of the grilling sub- L A scriber at substation A. Assuming that it is the subscriber at thecalled substation .l--l that is Wanted, thenpe-rator now tests.one` ot' the trunk jacks TJ as toits ,idle orbusy .condition by placing thc tipol the calling.. plug CP to the sleeve ofthe trunk ack- TJ and it the jack TJ tested leaflsto a busv first selector E,1 the sleeve of the jalr VTJ will ,have a battery potential upon Ait andthepperator will receive.theusual click in herl head receiver. Assuming that the l trunk jack TJ leads to an idle. Vfirst selector as E. the operator inserts the calling plug ,CP into theA trunk jackvTJ v and ,this insertion establishes an. energia: ling circuit for the slee-ve relay-SLI traced from battery through the windingvo't' tlux said relay SL2 conductor 206, ,sleeveI contacts of the connected plug-.CP and jackTJ to groundiandtherelaylSL upon energize-. tion closes- :its alternate contact- 209 closing --the continuity ofthetalkingconductor- *Assuming further thatf-the numberof the called subscriber at substatiolrH iS .2232.the

olzieratoii now actuates her -dial liey- Y-Qlfto clqses 21u-:energizing circuit for. the. primary.

BEST AVAILABLE oop,

relay PR lof theirst selector E traced from battery through the winding of the. said primary relay PR, conductor 207, normal contact 78 of the circuit switch S, tip contacts of the connected plug CP and jack TJ, alternate contact 210 of the dial key DK, impulse spring 211 of the impulse device ID, alternate contact 212 of the dial key DK, ring contacts of the connected plug and jack CP and TJ to ground at normal contact 8O of the circuit switch S. Primary relay PR upon energization, closes its alternate contact 208 establishing an energizing circuit for the motor magnet BIM traced 'from ground through alternate contact 208 of relay PR, conductor 214, normally closed Contact of the circuit switch S3, conductor 215, normal contacts 73 and 74 of the motor magnet MINI, through the winding of the said magnet MM, conductor 226 to battery and ground at normal contact 79. The motor magnet MM upon energization, attracts its armature 8 causing the pawl 16 which is engaging a tooth of the rack 11 to step the carriage C and secondary carriage SC one step forward in a horizontal direction. The secondary carriage is also carried this step, due to the arms 66 engag ing the notch 67. The armature L12, associated with the relay TWR and carried by the secondary carriage SC, supportsthe wiper arm 45 which carries the group wiper 51, line wipers 52 and 53, private wiper 54 and auxiliary wiper 55, the -sai'd wipers being normally two steps distant from their associated bank contacts, and upon-this first step of the switch the wipers are placed one-step distant from their associated bank contacts. Upon the first step forward from zero position, the buer 7 6 disengages contacts 75 permitting the same to assume their alternate position, opening the initial energizing circuit of the motor magnet MM. Upon the iirst step of the carriage C, offnormal wipers 90, 91, 92 .and 93 are also moved forward one step, wiper remain# ing in engagement with strip 84, wiper 91 engaging strip 86, and wipers 92 and 93 engaging strips 88 and 89, respectively. In the circuit, the circuit switch S4 represents wiper 91 and strip 86, and circuit switch S5 represents wiper 93 and strip 89, Strip 87 represents switch The wipers 90 and 92 and strips 83 and 88 are short circuiting strips and wipers for connection purposes with strips 85, 86 and 87, and strip 89 as is readily' apparent. That is, wipers 90and 91 are-electrically connected together and wipers 92 and 93 are electrically connected. By this arrangement, it is unnecessary to provide flexible cords for these switches. Switch S* moves to its alternate position upon the first step, closing its alternate contact 216, and the switch S5 also moves to its alternate position to close its alternate contact 217. The operator now actuates her impulse dia-l ID to send the first set of impulses Which are two in number, having assumed the number 'of the'called subscriber ats/ substation I-I to be 2322. These two Yimpulses cause two interruptions of relay PR causing tWode-energizations of the `said relay PR. Upon the first de-energization of the relay PR the closure of its normal contact 218 establishes an energizing 'circuit for the stepping magnet 219 of the pre-selectorswitch PSS the switch shown in Fig. 10) traced from' battery through the winding of the magnet 219, conductor 220, alternate contact 217 of the switch S5, conductor 221 to ground at'normal contact 218 ofrelay PR. By means of the` ratchet and paw] mechanism, the wiper 222 of the switch PSS isstepped into engagement with the first contact ,223.l The second impulse again de-A energizes the relay PR, againclosingthe' circuit for magnet 219 to steptheV wiper 222 into engagementv ivitl1 the second contact 223.' UUpon the'rs't step'ofthelswitchjwiper 222 off normal, o-normal contact` 224 ilsv sumes its alternate position, closinganenergizing circuit forfthefmotormagnet MM traced from g'roundat alternate contact 224:, through conductor 225, through alternate contact 216 of the switchS, conductor 215, normal contacts 74 'and 73, throu h"thewiIid- I ing-orn motor magnet MMvfan 'conductor 226 to batteryand ground at normal con-4 tact 79 of the switch' S. Q 5' The motor magnet MM upon its ener# gization causes the' carriages to `-beI ste'p'pedav second. step. in a forward direction.v j"This movement 'causes ywiper 91"to v4disengage strip 86 and engagestri 87 thereby causing (referring .to circuit diagram) theswitch S4 to open` 'its contact 216' and switch" S to close its.' alternate contact,227.` AThe switch is so adjusted that the primary relay delivers its' second impulse to fthe magnet 219 ofthe pre-' selectorswitch PSS to cause it -to move its wip'er 222 to the second bank contact 223 i.before Athe motor magnet vMM moves the group wiper 51 onto the first group contact 56, providing there is more than one impulse to be transmitted to' the 115 magnet. 219by the primary relay The magnet.Y MM is also.' adapted tol/'operate slightlyslower than the rate that relay `PR sends impulses to magnet 219 .to prevent the group wiper from being moved to. group 1.22.0

contacts beorerthe wiper 222 has been moved to the corresponding contacts '223, The motor magnet MM stepping the'carriage C and secondary carriage SC a second step, causes the group wiper`51 to en- 125 gage the first group contact56. The closing of alternate contact 227 of the switch S6 closes another energizing circuit for the motor magnet MM, which wasinterrupted when contact 216 assumed its normal posi'- 1,30

BEST AVAILABLE coa tion .on ,thei second horizontal' step of the switch, traced 4from ground at alternate con-` tact-227, over 'conductor 215, through contacts 7 3 and 74, Winding of motor magnet MM, conductor 226 to battery andground atnormal 3 contact '79net.v switch iS,v The motor i magnet MM. uponr energization, steps the carriages C and SC a,third step lin afor- Wa-rd xlirection, placingthe: group Wiper ,51 intoengagement Witlithe second group contact 56. @The .wiper 222. being grounded, places 'a r ground Vupon Ithe second contact 223 in which it remains in connection, the magnet-219 having ireceived Ativo impulses :from relay PR, thisground eritendsf ,over conductor 22,8,to thehsecond contact 56 of the group co'ntactsm'lVhen 'the'igroupl Wiper""51- engages, ,this groundedl contact, circuit is establ-ished lf o r.',the, IrelayTW'R ,traced "from batterythreugh the' wielding of relayl TWR oger ,conducton l229, through ,wiper 51,',l E'contact .256, l. conducltol, `228, vcontact 4223 land iviper,.222 to ground.' Thel relay, -'PWR upon. energizationl ,attracts Aits, armatures 42 and 43 and,(the attraction offarmatures43 bringsjabnt@ ,the 'mo-vmentfof the SPngs 68, 569,.',70 .and llft'o'fthei'rf alternate positionsand Ythe nc` sef432 of thefangular end 43A o'flithe ,armature drops 'int'olthe notches 50, andtheattraction of 'armature 42 causes. the armsf66 tto., cleavethe notches 67and causes the arm 45th' engage the :rail 64 or the plate 4,62., The motor 'magggnet.Ml/l. upon its third energization opens itsv contacts 7 3, 74 opening the 2circuitl oimagnetf MM which 'y again restores,V and closingofcontacts 73 and 74 again establishesa vcircuit for motor magnet M Mas heforeQdescribed, stepping the carriage'-fC'fforward a'j-ourth step.r The arm 45 :engaging the angular rail 64 of the plate 62 causes wipers 52, 53, 54 and 55 to engage thedirst set of ,contacts 58, 59, 60vand 6l. The energization of magnet TWR causes the `raising of the group wiper 51-rom engagement with the contact 56, but the Wiper 51 lis provided with 'an angular extension 51, -Which engages the angular portion 56 until the instant the Wipers 52, 53, 54 and 55 engage contacts 58, 59, 60 and 61, so that the4 relay TXVR" is insured of a positive and continuous energization until the first set of contacts is engaged. The nose 432 engaging the notch the'carriage support 30 asjawh'ole is carried forward in an angular direction dueto the arm 45 engaging the rail`6'4 fa`nd Vdue to the continued energizations of the 'inotorf magnet MM, the carriage Cfis' o course, stepped ina horizontal direction. Thevwipers 52, 53, 54and 55 having engaged the first set of contacts 58, 59, 6(1)` and, 6-1` shouldthe first privatev contact 60 bebusy, a substituate circuit for relay TWR is established after wiper 51 disengages contact ,56bl'eore relay TWR has de-energized, traced from battery through the Winding of relay TWR contacts and :71, conductor 230, conductor 231, Wiper 54,-to the grounded contact 60. r Theirelayl TVVR remains energized as long. as busy contacts are found., The relay TVVR remainingy energized,vr the j nose isheld tingtheslot 50 and the nent energization ,of MMV-steps .carriage C aus other horizontal 'step and -the. n'iovein'ent,l oi carriage C/moves the lWipers 52, 53, 54, andy A into engagement `with thesecond r:set of.: contacts 58, v59, 60,and61, Now zassuming disengage --the 'notch l50, thereby' permitting the Wipersfif, 53itljand;V v55 to-remainr'in engagementl-`with1,theselected set yof contacts 58,551,60, -and 61,' YTvhegarm,'45,resting ma @tarea-m11@ein 'ai hoidsifthe wipers iplace'athe-se1ectd cntafitsgfj The. 'Cloeing of ,contactv 68 ,of relay'fTiYR'supplije's a busy Pteiitial thrueh virer@ 15.4 te the lliilf tiple contact The continued energizationuand' de-,energization of 'motor' magnet MM steps 'the carriage C y'step by. step in y a horizontal Adirectifori untily it .has taken'its' twentysecond'step,.but the ca'rria'ie SC remains stationaryihrafter having selected an idle set fof; contact s, hut vthe angular movei ment ofthe secondary carriage support30 continues and thye'rod' v37 passes through the opening in thfblock38 Aofthe carriage The motor magnet, as before/mentioned, continuesnto' advance the carriage lC :until twenty-two steps "have been Staken by it. Upon .thetvventy-secondstep of the carriage C, the butter 81 engages the spring sets 78, 79 and 80 moving them to their alternate position. Thelclosing of "alternate contacts 7 8 and 8O extends the line .conductors Ito the idle second selector vandthe closing of alternate contact 7 9 of the switch S opens the energizing circuit of magnet MM, preventing further energization's'of the lnotor magnet ll'IM at this time. Upon the twenty-second step of the carriage :Cin a horizontaldirection, the cam edgej'19otthe plate 18 vvengages the post l20 moving they racll'l out ot line lwith the pawl 16 and the rack 12 in' operative relation with ytheI paw] 17""ot 'the motor magnet MM. A i 'r The idle second selector switch 1F having been seized, an energizing circuit' l'for 'the primary relay PR offgthe second' 'selector switch F is'established tracedffr'om b'att'ery through the windingjof relay BR', conductor 233, normal contact 234 ofthe 'sn'fitch'7STs Contact 58,' Wiper y52, [alternate 'Contact '78. tip vcont-acts of the connected plug and 'jack CP and TJ, alternate-contact 210i normal contact 211, alternate Contact 212', ringfcontacts ofthe-plug CP and jack TJ, alternate sume its alternate essi AvAiLAsLE coe* contact 80, wiper 53 and contact 59, to ground at normal contact 237 of switch SS. The contacts 78 and S0 are closed to cause the energization of PR before contact 79 is moved to its alternate position to supply relay 'RR with current. The primary relay PR" upon energiz-ation opens its normal contact 238 opening the release circuit, thus preventing a premature. release ofthe first selector switch E, The'clo'sing of alternate contact 289 of relay PR. establishes an energizing circuit for the motor magnet MM traced from ground at alternate contact 239 of relay PR", through conductor 240, normal contact- 241 of switch S", conductor 242, normal Contact 243 of MM, the winding of magnet MM', conductors 244 and 245 ,to battery and ground at normal Contact 246 of the switch S10. The magnet MM energizing, steps the carriages C and SC onestop, thus placing the group wlpcr 247, which is normally two steps distant, one step distant from the group contacts 252. The stepping of the carriage() allows lthe switch S9 to asposition and the opening oiits normal "Contact 241 opens the energizing. circuit of the motor. magnet liflvl as describedin connection'withA the first selector E. The ysecond selector switch upon its first step from zero; position allows the switch S1? to assumeits alternate position to open its normally closed contact 258, and the sw'tchS12- lsoassumes its 'alternate position closing itsnormallyopen contact 259. The switchI S1? also assumes its alternatevposition to,4 close. its normallyopen contact 260.,

TheA second selector having been selected audits first preliminary step taken, the operatonnow actuates her impulse device to sendthreefimpiulses of current which causes three interruptions of the circuit of relay,

PRK. vUpon the rstd'e-energization ot relay PR an energizing circuitis closed for the stepping magnet 261 of the pre-selector' switch PSS 265 of the switch PSS into engagementi with the first Contact 266 of the switch PSS. Twomore cle-energizations of rela)1 PR are brought about bythe impulse device ID causing two more energizations of the magnet 261, as i'ust described, to step the wiper into engagement with the third contact 266 which places aground upon the third grouplcontact 252 rendering it selectable, the ground extending from grounded wiper 265 through Contact 266, and conductor 267 to the third group Contact 252. T[pon the first step of the wiper 265 ofi' normal, the` otlflnormal contact 268 assotraced from: battery through the winding-ot the magnet 261, condu1tor' ciated with the switch PSS assumes, its alternate position, closes a.A clrcult for the motor magnet MM traced from ground through alternate contact 268, conductor 269, alternate contact 260, conductor 242, normal contact 2 43 of magnet MM, through the'winding of magnet iMM, conductors 244 and 245 to battery and ground at normal contact 246. As stated in connection with switch E, second selector l? is so arranged tha-t the motor magnet MM operates slightly slowerthan the rate at which impulses are transmitted, andgroup wiper 247 does notmoveonto a group contact until wiper 265 has moved o of la multiple contact, unless the wiper 265 is to remain in connection with such multiple Contact.

The motor magnet'MM upon energizetion opens its contact 243,interrupting its circuit, and upon de-energization again closes its circuit. The motor magnet thus steps the carriage C and secondary'car! riage vSC in a horizontal direction' and when the group wiper 247 engageslthe elected' contact 252, which is now' `g rounded,'anlener-f gizing circuit for the relayTWR is estab'- lishedv traced from;batteiyfthroughn the winding of the relay TWR. ,conductor 271,

wiperV 247, contitf252, conductor '267,lco'ii- ,Y

of ma'frnet M7M causes thesecodary carriage SC'to movelforward' in'an angular direction,causing the wipers,`246,` 249,l,250 and' 251 t o engage.' the firstsetgof pc'o'tats253, 254,255- an'df256'y and fshould tlvi'etA firstl set of contacts 'en g'a'ged: leadtoA con` nector, the private Contact 255 f'wouldfbe grounded`v closing'. a locking circuit for the relay ,"IVWVR traced from"battery through the winding of rela TWR, alternate con-1 tact 272 of' relay T R', conductors'273 and 274, wiper 250 tol the 'groundprivate contact 255. The initial energizing circuit o relay TWRZ is opened the instant the'lwiper's 246, etc., engage the first set of contacts '2 53, etc., should he set engaged be idle, for. purposes asalready described. The motor, mgnet MM continues 'stepping the carriages C and SC, 'and' thelrelay TW'R .remains energized due rtojth'e wiper 250engaging' successive grounded contacts,A 255,:funtil an idle contact 255 lis reached atwhich time the circuit of the relayTWR is opened due to the idle contact being free from ground. The wipers 246, 249, 250 and 251 remain in engagement withrthe idle sets of contacts 253, 254, 255 and 256 which lead to an idle connector G by the means already' described. T he motor magnet MM continues to step the carriage C and the carriage support of the carriage SC until the'twenty-second step BEST AVAILABLE COP isreached when switches S7, S2 and S10 assume their alternatepositiona the switch S2 closing lits alternate contact 246 and opening'tlie circuit of magnet MM, preventing further actuation of the magnet MM? at this time. The switches ST land Ss assuming their alternate positions close their alternate contacts 234 and 237, closing the continuity of the talking conductors and extend the calling subscriber to the idle connector Gr selected." lAs before stated, S7 and S2 operate before S10 closes the circuit of RR. The primary relay PR also restores due tothe contacts 234 and 237 assuming their alternatepositions.

Upon the'closure of contacts '234 and 237 an energizing circuit for 'the primary relay PR2 of the connector Gr is established, traced from battery through the winding of the primary relay PR2, normal contact 275 of the switch S15, normal contact 276 of switching relay 277, contact 253, wiper 246, alternate contact 234 of switchS?, contact 58, wiper 52, alternate contact 78, tip contacts of. the connected trunk jack lTJ and plug CP, alternate Contact 210, normal con tact 211, alternatecontact 212, ring contacts ofthe `plugCP andjack'lTJ, alternatecon- 9.; tact80, wiper 53, contact 59, alternate contaet( 237, wiper 249,; contact 254V and normal contact A27,8 off relay,v 277 to ground at normal contact 279 of the switch S16.A Theprimary relay 13H2 upon its energization closestits alternatel contact 2807 and opens itsf normally closed contacts' 281, 28.2. The closing of alternatecen'tact 280, offirelay PR2 establishes y an' .energizing circuit lfor Athe motor magnet` MM2 of the connector lGr Atraced from ground at', alternate contact 280, throughV conductor 283, norma-l contact 284 of theswitch S17, conductor 285,',normal Contact 2860i magnet AMM2I and! through thetwinding otinaginet to battery f and ground. Then iagnet MM2 upon energization, steps the carriage C and secondary carriageSCone step in a horizontal direction. Yhen theswitch takes its Vrst step from'zero p ositiom the alternate contact-284 of the switch vS17` opensthe initial energizing circuitI ,of magnet'MM2. i The switches S18 and, S,12,`,upon the first step of the switch, assumetheir alternate positions, switch S18 openingitsnormal contact 287 to prevent a premature release circuit being closed when relayv PR2 is de-energized, and .switch S19 closing its alternate contact 288 to prepare a circuit for magnet 289.

The operator now actuates *her impulse deviceID, sending .two impulsesof current causing two interruptions of the circuit oi primary relay PR2, and upon -the first decncrgization.ofrelay lPR2 an energizing cir` cuit is established for the stepping magnet 289ofthe pre-selector 'switch APSS2 traced from batterythrough the winding of inagnet 289, conductor 290, alternatel contact 288, conductor 291, normal contact 292 oi' the switch S20 to ground at normal contact 282A of relay PR?.- The magnet 289 steps the wiper 293 of theswitch PSS2 into engagement withthe first contact 294 with which the wiper is associated. The switch PSS2 is the same as the switch shown in Fig. 10. The second cle-energization o1' relay PR2 causes a second energization of magnet 289 causing the wiper 291 to be stepped into engagement with the second contact 292. Upon the firststep of the wiper 293 oii" normal, its off-normal contact 294 moves to its alternate position and as switch S has closed its alternate contact 284, an energizing circuit is established for the magnet MM2 traced from battery through the winding of magnet MM2, its normal contact 286, conductor 285, alternate contact 284 to ground at alternate contact 294. The magnet MM2 steps the wiper 295 into engagement with' the first contact 296. Y The wipers 297, 298, 299 and300 are also stepped, but at this time do notengage any of the contacts 301, 302, 303 or 304. Upon the second step of the switch, switch S21L assumes its .alternate position closing its alternate contact 305, closing circuit for the magnet MM2 traced from battery through magnet MM2, its contact 286, conductor 285 and alternate contact 305 to ground. Alternate contact 284 of switch S17 is opened upon the second step of magnet MM2. This steps the wiper 295 into engagement with' the second contact 296 establishing an .energizing circuit for the relay VTVVR2 traced from battery through normal contact 306 of switch S22, conductor 307, through the winding of relay TVVR2, conductors 308.and309, wiper 295, contact, 296, conductor 310, and contact 294 to grounded wiper 293'. VT he wiper 293 being permanently grounded,'places a ground upon the selected contact 296, making it selectable by the wiper 295 when it engages the same. Thel relay TTR2 upon energizationattracts its armatures 42 and 433 (Fig. 9) and the attraction of armature 433 causes the said armature to withdraw its nose from engagement with notch 50.', and the armature '42 upon attraction withdraws the arm 662 from the notch 67. The movement of armature 42 causes arm 45 to engage the rail 64 of the selected 'group and the further actuation of magnet Mii/12, due to the closed contact 305 and 'its interrupter contact 286, causes the carriage C and the support for secondary carriage S to move in a horizontal direction, but the secondary carriage SCjremains stationary, due to the engagement of arm 45 with the rail 64, and the rod `37thus slides through the opening in the support 36.

The relay TVR2 remains energized until contact S22 is opened.- Upon the eleventh BEST AVAILABLE copi.

step ot the carriage C ofi' normal, the switch S21 opens it-s contacts to open the energizing circuit ot' the motor magnet MM2 and the switch comes to rest. The switch S22 also opens its contact 306 bringing about-,the deenergization of relay TWR2 and the switch S23 also assumes its alternate position, closing its alternate contact 311, as does also switch 2 causing it to close its alternate Contact 292. The relay TlVR-2 cle-energizing permits its armature to drop into a notch 50 on the pivoted rail of the carriage SC'.

The operator now actuates her impulse device ID to send two impulses of current, which impulses cause two interruptions of the primary relay PR2 which brings about two energizations of the stepping magnet 312 associated with the pre-selector switch PSS2, traced from battery through the winding ot' magnet 312 and alternate contact 292 to ground at norm-al contact 282. Each time relay PR2, is de-energized, magnet 312 rotates its wiper 313 one step. The switch PSS3 is the same inv construction as the switch shown in F ig. 10. The stepping magnet 312 steps its associated wiper 313 of switch PSS3 into engagement with its second associated contact 314, placing ground upon the second contact 304, rendering it selectable. Upon the firststep of the wiper 313 oit normal, its off-normal contact 315 asi connection with'the selectors, the magnet MM2 operates slightly slower than the rate that impulses are transmitted and the wipers 295 and 300 are not moved into engagement with contacts 296 and 304, respectively, until wipers 293 and 313 have moved o'of multiple contacts 294 and 314, unless the wipers 293 and 313 are to :remain in engagement with selected contacts. Upon this step of the carriage the switch S22 again closes its normal contact 306 and opensl the contact 311 of switch S23 and allows switch S22 to assume its alternate position to close its alternate contact 316. The relay TVVR2 upon restoration, as before mentioned, causes the nose of its armature 433 to engage a notch 50. The arm 45 engaging the rail 64 causes the carriage SC to be moved in an angular direction to place the wiper 297, etc.. into engagement with the iirst set of contacts 301, etc. The closing ot alternate contact closes an energizing circuit for the magnet MM2 traced from battery through the. winding ot MM2, contact 286, vconductor alternate contact 316, conductor 324 to ground at normal contact 325 of relay 321. causing the wipers to take another step into engagement with the contacts 301, 302, 303 and 304 which are the contacts of the wanted line, and when the wiper 300 engages the grounded Contact 304, an energizing circuitis established for relay TlVR2 traced from battery at contact 306, through conductor 307, winding of said relay Tl/VR2, conductor 308, wiper 300 contact 304, conductor 317, contact 314 and wiper 313 to ground. The relay TVR? again attracts armature 432, withdrawing its nose trom the notch 50. The wiper arm 45', when the wipers 297, 298, 299 and 300 are engaging the contacts 301, 302, 303 and 304 ot the wanted line, is engaging a notch 65 in the rail 64 to hold the wipers in position. The motor magnet MM2 continues stepping the carriage C and the secondary carriage support as described in connection with the selector, and when the switch makes its last step, switches and S1G assume their alternate positions closing their respective alternate contacts 275 and 279, and the switch S25 also assumes its alternate position closing its alternate contact 320. The closing of alternate contacts 275 and 279 establishes an energizing circuit for the relay 321 traced from battery through the winding of relay 321-conductor 322,l ali-- ternate contact 279, normal'- contact 27 8, cont-act 254, wiper 249, alternate contact 237, contact 59', wiper 53, alternate contact 80, ring contacts of the connected plugand jack CP and TJ, normal contact 212, through the windings of the polarized relay PO, alternate contact 207, normal contact 210, tip contactsv of the connected plug CP and jack TJ alternate Contact 7 8', wiper 52, contact 58, alternate contact 234, wiper 246, contact 253, normal contact 277'to ground at alternate Contact 275. The flow of battery through the relayfPO is of such ak direction that the relay PO attracts its armature to close' ,itsf alternate lcontact 323 to light the calling'lsupervisory lamp CL and notify the operator that the called subscriber at substation H has not 'answered'.` The relay 321 upon energization opens normal contact 325 opening the circuit of motor'magnet- MM2, preventing further stepping vof the switch. The contact S49 is opened upon the' twentysecond step ot tlie'magnet' MM2 before relay PE2 cle-energizes' and contact S4o remains open until the switch returns to normal.

aZZecZ Zine idle. y

`Oli,

BEST AVAILABLE coreL tor 329 through the winding of relay CO to ground. The relay CO upon energization removes the substation control of line relay LR', and the relay STR upon energizing opens its norma-l contact 330 disconnecting the b-usy back apparatus BB and also closes an'energizing circuit for Wiper y'control relay 500. The closure ot' alternate contact 331 of relay STR establishes an energizing circuit for the ringing relay RI traced from battery at alternate Contact 332 or' relay 321, over conductor 333, through the winding of relay RI, normal Contact 334 ot' relay 335, conductor 330 to ground at alternate contact 331 of relay STR. The closure of alternate Contact 337 ot relay RI connects ringing current to the called substation H traced from the generator GE, through the interrupter I, conductor 338, contact 337, wiper 2 7, contact 301, through the call bell and condenser at the substation H back by Way of contact 303, wiper 299, alternate contact. 339, normall contact'340 of relay 335, through the winding of said relayV The calll bell at-the 'called 335 to battery. substation H is thus intermittently rung and the saidringing current is disconnected on either a ringing or a silent period.

Should the subscriber at substation-H an-v swer during a silent period, the ground at the interrupter I wouldl close a circuit for the relay 335 through the now closed switch hook contacts and should the subscriber answer dur-ingla ringing period, .the combined generator land battery. flow'` .through the closed switch hook contacts and through the relay 335 will-bring about its energization, The opening of normal contact 334 of relay. opens the .circuit of relayRI-todiscon--l nect `ringing current, and the closing ciale; ternate contact 340 establishesa'l locking cir-, cuit for relay 335 traced from batteryV through the lwinding' of said relay; 335, its

alternate contact 340 to groundat alternate contact 320. The closing of alternate con.-Av

tacts 341 and 342 ofrelayr 335 establishes a circuit for the battery switching relay `277 traced from battery through the lower winding of relay 277 over conductor 344, Ythrough alternate Contact 342, conductor 345, normal Contact 339, wiper 299, contact 303 through the substation back over contact 301, wiper 297 normal'contact 337, conductor 346, alternate contact 341, conductor 347'. and through the upper winding of the relay 27 7 to ground. The closure of make before break contacts 348 and 349 causes a change in the direction of the battery owthrough the polarized relay PO of the cord D. The circuit of the relay 321 now extends from battery through the Winding of relay 321, conductor 322, contact 279, conductor 350, alternate contact 34S passing over the heavily marked conductors, and through relay PO back over 'they lower heavily marked conductor, through; alternate contact`349, conductor 351 to ground at alternate contact 275. The flow of current through relay POA is such that the contact 323 is opened to eacey the signal CL, notitying the operator that the called subscriber at substation H has answered. The subscribers at substations A and H are now in conversational circuit, the talking circuit being traced over the heavily marked conductors.

Release.

Assuming nou7 that the subscribers at the calling substation A and the called substation H have finished conversation, they replace their receivers upon their respective switch hooks and the replacing'of the receiver by the subscriber-at the calling sub-4 stationA opens the. energizing circuit for supervisory relay SR, andthe relay SR restoringcpens its alternate contact 203 and again closes its-` make before break ycontact 202, closlng an 1 energizing circuit or'the supervisoryk lampxAL traced from .battery through the-supervisory lamp AL, contact 202, sleeve contactsf of -the connected plug APlandjack J throughrthewinding.of the cut-oli1 relay CO Inground, thus lighting the supervisoryv lamp AL .and notifying the op-A ground atalternatel contact 323, thus light-` ing the said supervisory lamp C-Lvand notitying the operator that the called subscriber at substation H has replacedhis receiver.

The operator noting the two-lighted supervisory signals AL and CL knows that the respective subscribers-at substations A and H have replaced their receivers, the said operatornow withdraws the plugs AP and CP from the' respective jacks J and TJ. The Withdrawal of the plug jAP opens the cir. cuit for the ,cut-olf relay CO and supervisory lamp AL, the said relay CO restoring to normal and the supervisory lamp AL is eifaced. The withdrawal of the plug CP opens the circuit for the sleeve relay SL, the said relay SL restoring, and the polarized relay opens its alternate contact 323 to efface the supervisory signal CL. The appa ratus of the cord circuitD is now at normal and available lfor establishing otherv connections.

Thewithdrawal of the plug CP from the lli) BEST AVAILABLE cop.,L

jack TJ opens the energizing circuit for the normal contact 281 of relay PE2, conductor relay 321 of the connector G and the said relay 321 restoring, closes its normal contact 325 establishing an energizing circuit fofr` the motor magnet MM2 traced from battery through the winding ofthesaid magnet MM2, through its normal contact 286, conductor 285, alternate contact 316 of switch S24, and conductor 324 to ground at normal contact 325. It will be remembered that on the last step of the carriage C in a forward direction, it caused the rack 12 to be shifted into operative relation with the pawl 17 so that upon the operation of mugnet NIM2 the pawl 17 engages a tooth of the rack 12 and moves the carriage C and secondary carriage SC back one step. The motor magnet MM2 is thus energized and de-energized due to the opening and closing of its interrupter contact-286. The carriage C and secondary carriage SC are stepped back to normal. The lug 67 engaging the arm 6,62 removes-the, .wipers from engagement-with the-bank contacts' andthe arm 45 from'engagement with the rail .64. The switch S4? closes its alternate contact 503 upon the firstbackward step of the carriage C and this contact remains closed until the switch carriage ,C reaches its normal position. .The ,wiper control relay 500 disconnects the line wipers from the switch while the switch is moving back to normal. The' switch A carriage upon reaching normal opens contact'503, Vthereby opening the circuit of magnet lWMZ.

Upon the'first step ofthe carriages in a rearward direction, switchesS15 and S1 assume their normal position `to close normal contact y27 5.and 279, asdoes switch S25,

f and the shifting of itsv contact` 320 opens Vof the second selector F, as will presently be described. The return of the carriage C of the connector causesa lug, which is suitably secured to the carriage C, to engage the retaining pawls of the switches PSS2 and PSS3A moving'them out of engagement with the ratchet wheels to allow the wipers 293 and 313 of 'the respective switches PSS2 and PSS3 to restore to normal by spring tension. The retaining pawls are held out of engagement with the ratchets until the switch carriage again moves oli' normal. The switch upon reaching normal again closes contact S4".

A circuit of release relay RR of the second selector -F is established. as above pointed out, over a circuit traced from ground at normal contact 287 ofswitch S18T 360, Contact 256, wiper 251, conductor 361, winding of relay RR to battery and ground at alternate contact 246 of switch S1".v .The

relay RR upon energization closesits Valternate contact 362 establishing an energizing circuit for the motor magnet MM, traced from battery through alternate contact 362, conductor 244, through the winding of magnet MM', normal contact 243 to ground at alternate contact 270 of switch S14. The magnet MM is energized and immediately de-energized due to the opening of-its alternate contact 243 and this actuation of MM moves the carriages back one step. Upon this first step, switch S10 assumes its normal position again closing its normal Contact 246 so that when the wiper 251 disengages contact 256, the circuit of motor magnet MM is maintained at normal contact 246., The circuit of magnet MM thus extends from battery at normal contact 246, over conductor 245, through the winding of magnet MM and its normal contact 243 to ground at alternate contact 502 of switch 43. The contact 502 is closed upon the first backward step of the switch and remains closed until the switch carriage reaches normal. vThe magnet MM is thus energized and de-energized and foreach de-,energiza-vtion of magnet MM', the carriagesV are' stepped back step by step. Upon the first step of the carriage back to normal, v4the switches S'I and S8 assume their normaly positions to again close their normal con-' tacts 234 and 237. The carriageA when reaching normal engages the holding-pawl of the switch PSS moving it out of en gagement with its associated ratchet to allow the wiper 265 to restore to normal, and restores off-normal contact 268 to normal. The switch carriage normallyholds the holding pawl of the switch PSS2 out of engagement with the ratchet of said switch. The return of the carriage to normal again closes contact 258 of switch S11 and opens contact 502 of switch S43. The carriage returning to normal causes the upwardly eX- tending lug 90 to engage the arm 66 to restore the switch carriage SC to normal. The switch F is now at normal and'available for use. The closure of normal contact 258 of switch S11 establishes an energizing circuit for release relay RR of first selector E, traced from battery through alternatey contact 79 of switch S2, through the winding of relay RR, wiper 55, contact 61, normal contact 238 to ground at'normal contact 258. The closing of alternate contact 370 of relay RR establishes an energizing cir cuit for magnet MM traced from battery through alternate Contact 37 0, through the winding of magnet MM, normal contact 73, conductor 215 to ground at alternate contact 227 of switch SG. Upon the first rearward visoi'y 55 BEST AVAILABLE con.

step' of the magnet BCM. contact 501 is closed and remains closed un'til the switch carriages and SC reach normal. The switches E and PSS are restored in a manner similar tothat described ir. connection switch F. Referring to Fi 9, it will be noted that switches S18 and S are end Springs which are moved by the first step of the switch carriage from normal and are returned to nrmal by the return of the switch carriage to normal. Switches S15, S and S25 are end springs operated on the twenty-second step of the switch carriage from normal and are restored by the first return step ofthe switch carriage. Switches S,`S". S" and S24 are controlled by wiper 520 and its co-operating contact strips. Switches S2.o and S22 are controlled by wipers 521 and 522,4 respectively, and their co-operating contact strips. y f

Called Zin@ busy.

' Should the'called subscriber atsubstation H bebusy, the connector bankl privatecon tact 302 will .be at a batteryV potential and when"the wiper 298 of the' connector 'G en esblished fdr muy STR as; both terminas of said relay'ST R are connected tof battery,

'and the relay" STRwill 'fa-il 'to energize.

Therclay STR -ailing to eneigie, not

`r1`nitthe wip'r control relay 500'to energiz'e and'cnnct the calling line to tliebsy called' line. The relay STR remaining-at normal', connects the busy signal fimfbu'sy back apparatus' BB throudh its normal coiltact 330 over the-vertica side-"f the line fthiougli alternate contacts 27 '5`, cnt'act'-276, Contact 25a, wiper 24a-alternate' contat 254,

-fc'on'ta'cxt 58, wiper 52, alternate contact'78,

tin 'contacts of the connected plug andV jack CP' and TJ, normal contact- 210, alternate contact 207, tip contacts off the connected plug and jack AP and J through the calling substation A, back through'the ring contacts of the connected plug: and jacl'r`AP and .l and through the lower winding of rela-y SR to ground. The calling subscriber at substation A hearing thebusy signal replaces his-receiver upon its switch hook, bringing about the de-energization of relay SR, which relay SR restores to close a circuit for superlamp SS. The called line bein'g busy, relay'STR remains at normal and no cir- 'cuit is established for relay -RI and 335 and 227, a's is readily understoodfrom the previous description. Polarized relay PO is energized to close its contact 323' to light supervisory lamp SS as previously described, and if the operator had her listening` key thrown. she would also receive the biisy signal. The operator noting th'e two lighted supervisory signals SS and SS wvithdraws the plugs AP and GP -rom the..

4with said bank of contacts,

'I contacts "then A group and for restoring said active-contact 'es the Abusy contact 302, nfcir'cuit is means controlled bodirnent of my invention, 1t is apparent that it may be applied iu various ways and also that many modifications and changes will readily suggest themselves to those skilled in the art. Therefore, I do notl desire to be limited to the exact structure as shown, but aim to cover all that which comes within the spiritl and scope of the appended claims.

What I claim as new and desire to secure by United States Letters Patent, is:

1. A two-dimension automatic switch provided with a bank of contacts divided into groups, a movable contact for cooperation mechanism operatively associated with said movable coutact for controlling the movement of said movable contact, and a dvingniagnet operativelyv associated with said mechanism for advancingsaid active contact'to la group 'of to? a contactin the elected to normal in a retrograde direction.

2. An automatic' telephone system including contacts arranged :in groups, a wiper adapted to engage' all 'of said contacts, a

select a grouo. said ratchet also serving to continue travel 'of said' wiper to select a contact of the selectedgroup, means dependent upon the connections of the con? tacts encountered by 'said'wip'e'r for automatically causing the said-continued travel of said wiper, a motor device for coopera- 'tion' with said ratchet in advancing said calling lines, auxiliary selective switches one for each selecting switch, means for directively operating said auxiliary switches, said means including a relay controlled over a pair of talking conductors in series by a series of interruptions of the series circuit, by said auiriliary switches for automatically causing travel of 'said selecting switches to correspond to the extent of travel of their respective auxiliary switches, mechanism for thereafter continuing the travel of said selectingT switches independently of said auxiliary switches. said last mechanism also including means for returning the circuit selecting switches to normal in a retrograde direction.

@LA semi-automatic telephone system BEST AVAILABLE COF.

including link-circuits, farrangedf lin groups, a'selective switch having multiple terminals of said link-circuits arranged in corresponding groups, group contactsf at said switch one tor each group, movable contact members adapted to'connectwith said multiple terminals, apparatus, including a relay controlled over a pair of'talking conductors in series vby a series ointerruptions of the series circuit, for causing travel of said contactmembers to select a group,rmecha nism sensitive to the electrical condition of said group contacts determining the selection of the group, and means tor-'thereafter continuing travel of said members to select terminals of the selected group.v .1'

5. A telephonesystem including an automatic switch provided with a normally-'at rest contact maker, meansfor transmitting current impulses over the two sides of, a talking circuit in series from acontrol point, a control device individual to said switch set'by said impulses in a position dependent upon the number ofcimpu'lses transmitted, and means for advancing said contact l'naker to a selective position dependent upouthe lposition at (which Asaidl lcontroldevice is set, said meansv also` beingi operative* to restore saids contactmakeriinl f the samefpath in which said contactmakerVIA isfa'dvanced." Fifi;

6.' "A selector 'comprisingf a normally ftrest movable switch ^membe'r', said movable switch member movable 1n a-'lineardirec- -tion only, preselectormechanism individual thereto,` an electromagnctie step-byssteprf device responsive toI selectingrimpulses transmittcd lover the two-sides of a-talk'ingfein cuit in -series1by'a"`number of linterruptio'ans of said series circuit for adjusting?) said mechanism, a 'source ofj motive? 'power i'or advancing ysaid switch member, 'said-.mechanism being eifectivefaccording to its-selec'- tive adjustment for cuttingloi the'ap'p'lical tion of Vmotive power j ronr "saidfswitch .melfnben-A A 'Y gri? fureur:-

y"1' A selector" comprising contacts and fa normallyr at rest movable-switchjmember driving means forsaid switch member, said switch memberV being movable in'k a ,linear direction"only, anv electromagnetic-ally Lad; j ustedvstep-by-step" device individual Ito' said member andV responsive to selecting' impulses transmitted 'over the twofsi'd'es of" a talking circuit in seriesfrom a controlpoi'nt'by in"- terrupting said series circuit a 'numberof times, and means for causing said driving mean'sto adjusty and 'stop said switcli'me'mber according to the adjustment' of said' device, said drivingmeans also being operative to restore said switch member'to normal.

8. In a telephone system, a' `calling and a calledsubscribers line, automatic switches for uniting said lines for conversation, groups of contacts for said switches, each of said switches beingprovided with a shaft and contactvwiper'sfhaving primary movements to selecta group ot contacts and secondary movements to select a Contactin a selected group of contacts, meansincluding a single driving means for producing both movements and for restoring the switch shaft in a retrograde' direction to normal.

' 9. A telephonel system including a connectingcircuit, a selector switch controlled over the two talking'conductorsof'said circuit in series by a seriesof interruptions of rent for4 said selector.

Y 10.1 A. semi-automatictelephone system iii'- cluding aiy selective'switch, anV auxiliary switch' `therefor',f af'conta'ct wiper for said xiliaryswitcm stationary' contacts adapted r-to' bev engaged thereby, 'stationary contacts' for said selectiveswitch', connections 'between the"contactsjof"said two switches,- a contact' wiper for: 'said selective switch yadapted 5to engage? its 'said' stationary contacts', a calling telephoner linel operatively connected! with 's'a'idfswitchesg imechanism for transmitting'directive' currentsA over: the two talking conductors of a circuit in series Y' by 105 'interuptigisaidi"series circuit ia' number o f ftinzie's;'appaatiisfrcsponsvey to said currents for fcausiiig ff travelY off; the contact 4wiper of said auxiliaryr f'switchy'f'and mechanismfincluding l'sa'.id "stationary 'conta'cts ot` fboth Vsvvitcl'ies '1 for Y automatically 'causing travel of 'said contactwiper of said selective" switch 'corresponding to tlietravel of the auxiliary 11.V A semisautomatic telephone system including trunk circuits vhaving multipleterminals =arranged in' groups, group' contacts 'onefior each group, a selective 'switch,-1a group private wiper' therefor adapted to moveover said group'contacts. an individual private'wiper therefor adapted to engage thev multiple terminals 'of all said' groups, mechanism for altering thenormal'electrical vconditions of said group contacts, -mechanism for altering the' normal electrical conditions of 'said multiple' terminals, and means controlled over .the twotalking conductors of at'circuitinseries by interrupting the series circuit a series of times for operating and releasing said selective switch. 

